Field of the Invention
The present disclosure relates to an image forming system which comprises an image forming apparatus such as an electrophotographic printer and various accessory devices connected to the image forming apparatus.
Description of the Related Art
An image forming system is configured by an image forming apparatus and an accessory device. In the system, the accessory device, such as a sheet feeding device, a stacker, a book binding device, a finisher and the like, are connected to the image forming apparatus. The image forming apparatus and the accessory device of the image forming system are connected through a bus topology network to establish data communication therebetween. By freely configuring each device, high-speed communication can be established through the bus topology network.
Each device forming the image forming system has type identification information, which is unique to a type of device and is called node ID. It is generally known that, in bus topology, device is identified by the node ID to establish communication between devices. Here, if the node ID overlaps, accurate communication cannot be secured, which causes malfunction. Further, each device connected to the bus topology network is capable of recognizing the type of device connected by the node ID. However, it is difficult to physically recognize an order in which each device is connected unless performing some methods for identifying the connected device each time the device is connected, etc.
In case of the image forming system, it is general that the node ID is managed by the image forming apparatus. The image forming apparatus holds a connection order of the accessory devices in the built-in memory. Then, the image forming apparatus compares the detection result obtained by the detection of the connection state by performing the method for identifying etc., with the connection order held in the memory. Through this, the image forming apparatus confirms the connection state. If the connection order held in the memory does not match the detection result, the image forming apparatus notifies a user that an abnormality has occurred in the connection of the accessory devices and prompts the user to take some appropriate actions to solve the situation.
For example, in Japanese Patent Application Laid-open No. 2007-062166, when the connection order held does not match the detection result, an image forming apparatus displays a message to prompt a user to take some appropriate actions. In the message, the user is prompted to disconnect the accessory device found to be inconsistent with the detection result; to turn on power source again; or to reset the connection order of the accessory device. In US2007/0086045 (A1), when the connection order held does not match the detection result, the image forming apparatus displays a message. In the message, the user is prompted to input an instruction to disconnect the accessory device to make the apparatus available. In Japanese Patent Application Laid-open No. 2007-076006, when the accessory device is inoperable, it is prompted to reset the connection order of the accessory devices when setting the connection order of the accessory devices is set.
As mentioned, conventionally, the setting of the devices, including determination of the connection order of the devices or prevention of the overlap of the node ID, is performed by a user or a service person of the image forming system. Since it is the users that work when introducing or changing the configuration of the image forming system, wasteful works or operational failures due to wrong setting may be caused.